Replace tubes yearly?

@larryi you make a good point about tube testers, most testers also don't test the tubes at the same operating parameters that they will be used in.

I second the recommendation for the early Sylvania 6SN7 tubes. Specifically the ones with the triangular plates. 
Hilarious, normb.  When I worked in a high-end audio emporium back in the late eighties/early nineties I used Aerial Boundaries as my initial go-to demo. The repetition in it makes for great comparisons between components.  I probably owe Mr. Hedges $$$ in royalties :) 

Gotta keep in mind that how long a tube lasts and how long a tube sounds its best are two completely different things. Are there parameters you can test for this?

@normb ,

Beautiful Shepherd!

@normb 

Hello Norm..

‘Your are the third person who likes the Sylvania 6SN7 Chrome domes from the 40s or 50s.I have bought from Brent Jesse before and Andy at Vintage Tube services is great too.

I am experimenting with my solid state gear, I have Pass Lab preamp, First Watt Sit-4 going into the Volti Audio speakers going to put a Modwright Analog Bridge between the preamp and amp and it takes the 2x6SN7 or 2x6922s with a flip of a switch…so should be interesting how that goes..https://youtu.be/t0s8_WLu_T4?si=6tg9eunJJ20Lr-q2

@thecarpathian Thanks. That was Hudson Shepherd, a service dog I had for nearly 6 years having rescued him from a local (DC) shelter a 18 months. It’s been a year since I had to put him down due to canine myelodysplasia - like ALS, Lou Gehrig’s disease. He helped me get over some PTSD. Loved kids. Never could eat a whole one though.

@silverfoxvtx1800 I liked those so much I bought a second set from another seller.They test well (I own a TV-7 D/U tester) and sound as good but I believe you said “warmth.” There’s just SOMEthing about the airy/soundstage from the lower gain (mu=20 max) tubes I prefer and I own a handful of matched pairs that just do it for me and my system.

Off-topic here but some good reading:

https://www.head-fi.org/threads/6sn7gt-6f8g-an-exploration-of-wwii-era-octal-tubes.890205/

I turn my tube preamp off after use.  If you are really concerned just get the tubes tested.

@normb 

thats a excellent tube read Norm thanks…

If you use tubes that will eventually need replacement, get a complete set of replacement tubes.  You can "test" the old tubes by swapping in tubes from the reserved set; if the sound improves enough so you are willing to replace the old ones, you already have the replacement(s).  This subjective testing is probably more meaningful than most measurements on a tester.  

Remember: all old and worn out tubes can be sold on eBay (just kidding, throw them away).

I agree that the answer is no, but as a tube enthusiast, I always have back up tubes and periodically switch out tubes to compare the old with the new to make sure everything is in top order. This takes organization and good notes to keep straight.

My audio research vm-220 has 12 tubes (8 x 6550) per mono block, but still sound glorious when manually biased. Pre-covid it was $1600 to replace all my 6550s (16 or matched octet) by audio research. Only had to do this once in 20 years. But with the California heat, I have now switched over the Aesthetix amps (I bi-amp Atlas monos & stereo amps in my small room and only need to consider one power tube per channel. Much simpler and a lot less heat while enjoying the sound year round.

For those interested in learning more: The www.audiophilefoundation.org recently had a zoom discussion on tube testing with a known expert and offered best practices. Which tube tester and which areas to check to look for with tubes make a a big difference. Members can go to the website and look at past events to watch the zoom (cost is $30 annually gets you lots of other benefits too).

I think the tone of the 6SN7 tube is naturally full and warm. The Ken-Rad VT231 has the most solid bass, while the RCA or CBS Hytron 5692 has the smoothest sound. Overall, in my Cary SLP05 and Schiit Freya+ and Saga I like the Raytheon VT231 for best overall sound. But lots of good ones. Best from WW2 VT231, JAN 6SN7 from 1950’s, and 5692. Just my experience- these all seem very reliable.

Amplitrex AT1000 is the tube tester to buy.

https://amplitrex.com

Tests multiple variables on most audio tubes.

As OP I have nothing to add to the great technical advice given in this thread.

I do wish I could remember which Audiogon member sent me those tubes a few years ago. It was a very gracious, and trusting, thing to do for someone he’d never met anywhere but here.

I will also say that in the last year or so I get a little bit of speaker hum when I first turn my system on. It goes away to complete silence after about 5 minutes. This is an old system so I guess it could be anything but it makes me wonder if it might be a tube. I may get a back-up set just to test it.

But, I confess that I absolutely hate messing with my system, fooling with cords and pulling components out. I guess some people enjoy that but I don't.

I have, and like, the Amplitrex tester.  It is simple to use, tests at full power so the tubes are measured under stress, and it displays both test measurements and the specified values to compare the results to.  But, one still needs experience to know what the results mean as to whether or not the tube needs replacement.  The biggest downside to this unit is that it is expensive.  There are kits for testers that experienced tube professionals like.  One expert who owns well north of a dozen testers, including several Amplitrexes said that his favorite is the kit called the e-Tracer out of Taiwan.  Hooked up to a laptop, it will curve trace the tube (the Amplitrex can do that too).

I wouldn't know what once a year is since random tubes blow at different times, and I don't keep track. When a tube blows I replace it. In my ARC gear some tubes doing the same work as others (output stage, for example) blow much before the others. I buy the same brand of tube and do not really hear the difference when I replace one tube in a pair (output, input, etc.) and I'm listening to an old paired with a new. I guess I'm a lazy audiophile or else I'd have a chart and keep track.

The adage, if it ain’t broke, don’t fix it ... comes to mind

I will often leave my Allnic Audio A-6000 300 BXLS tube amplifiers on 24 seven they are on at least 12 hours a day every day for the last five years, I have an AT-1000 Amplitrex tester, they are still testing in the low 80% range.

the amplifier has bias adjustment metering for each tube, I check it daily and have never noticed any kind of drop, it goes up or down a little based on AC coming out of the wall, but that's about it

Bottom line ... every circuit is different, every tube situation is different, if the amp sounds bad or the tube goes bad, you will notice, if you didn't notice, then everything is fine. 

I have been using tubes for 56 years so you would think that might make me an authority but I will make no such claim. Just my experiences, these are what they are:

I used a Dyna Stereo 70 and the Dyna MK IIIs for 17 years. The tubes tended to last for 2-5 years. I think for the Stereo 70 those are the 7199 and the 5AR4 and one or two others, for the MK IIIs those are 6550 and a 6AN8A, and there’s maybe another? I am having difficulty remembering.

I switched to the NYAL Futterman OTL3s in 1985. For 10 years, they were a little unstable. One meltdown was my fault: I experimented with a pair of Duntec speakers that caused the caps to liquify, 😂.

But for the last 30 years, I have gotten 15 years (not a typo) out of the 6LF6 tubes. I just refreshed them last year with a completely NOS set of GEs. The tubes that got replaced still had 65% of their juice in them. The little tubes in the back have been replaced maybe once the entire 40 years that I have relied on the amps. I asked Jon Specter if I should replace them along with the 6LF6 tubes that got replaced last year, he said not necessary.

I replaced the tubes in the DYNA PAS preamp maybe twice during those 17 years. I have replaced the tubes in the Beard P505 preamp 3 times over 40 years. This last time, last year, the Beard got serious NOS Telefunkens, Mullards etc from the late 1950s / early 1960s.

The caps in the Futtermans got replaced in the mid 1990s, as stated, and again, when I replaced them just last year (along with the tubes), after 30 years of use, they were quite dried out and almost at the point of failing. I switched from the photoflood caps to three big mofos, I don’t know what they are but they are faster than the photoflood (the photofloods were the fastest back in the day, so I’m told), and more robust, especially in the bass.

As for on/off: the Futtermans get turned off at the end of the day. They are rarely running for more than 6 hours at a time, ever.

The Beard is left running 24/7 unless I am away for several days.

The Project phono stage is also left running 24/7 unless I am away.

As for tube-rolling: some tubes will sound different but not better. Some old tubes can sound better than new tubes. Some cheap tubes can sound better than pricy ones. I just had a situation where a cheap $50 Raytheon sounded better than a $350 Mullard. It’s system dependent. Trial and error.

@brianlucey

”…if you didn’t notice, then everything is fine.”

This is not true.

Parts slowly deteriorate. Some of that deterioration can cause a slow moving degradation in sound over a number of years. You don’t really notice. Then one day a part fails, you replace everything and then you notice what you’ve been missing.

It’s sorta like the frog in boiling water.

@audio-b-dog 

I'm not sure what you are doing or where the problem is... but having tubes routinely blow means there is something very wrong. I  run over fifty tubes and have for many years. I have never had one blow. Not one. Many thousands and thousands of hours of play time. I change them at recommended hours of running time.

I’m not an electronics guy. I’ve learned a bit along the way (how to change a tube, for example, and which tubes are for power, input, output, feedback, etc.) out of necessity. I have had a number of tubed pieces over the years, mostly ARC. I had an ARC PH-3 with three 6922 tubes and they never blew. I changed them because I wanted to find out about rolling tubes. I had a CJ Premier-14 preamp for a number of years and don’t remember changing the tubes.

So, what gave the most trouble were ARC Reference 2 Mk.2 and ARC reference 3 preamps. Often tubes didn’t last more than a few months. (I think there are bad tubes or faulty tubes that come out of manuacturing.) On both ARC preamps pretty much every type of tube blew. Output, input, power, etc. As I’ve gotten older, changing tubes especially in a preamp has become a giant pain in the ass. So, I sold the Reference 3 and bought a Pass XP-30 solid state which I love as much as the Ref. 3. Both great preamps.

I still own an ARC PH-7 phono preamp because I can’t find anything within my price range that I liked better. I bought the PH-7 used for $3500. I called every dealer in the U.S. looking for a used one and finally found a dealer in Canada who had just gotten one on a trade in. The tubes have been pretty stable in that one. It uses four 6922 tubes in a striaght line that power both channels. Supposedly they last for 2,000 hours, and the preamp counts hours, so I’m waiting for it to hit about 2,000 before retubing. I have used spares in a drawer in case an odd one blows. It also has a 6l6G power tube which has blown once. I’m not counting huors on that. I’ll just replace it when it blows.

Truthfully, ghdprentice, I hope I have your luck in the future. Because isolating bad tubes and changing them is a pain.

@audio-b-dog

Thanks for your reply. Really sorry to hear of your experiences.

Ok, you are unlucky in purchasing some malfunctioning preamps. I am assuming they were used... and they needed to be repaired. I know folks that have used tubed preamps for decades without blowing a tube... changing them or not. I have owned tubed equipment for more than a decade without failure. 

What I might do instead of REPLACE every year is to ROLL every year. I have a low power SET in the bedroom system who's tubes may outlive me. I've collected some used and new replacement tubes, and as it happens, intend to roll power tubes today.

Side question: When I look down into my AR LS-16 pre, each tube has a rubber collar around it. I don't see those on tubes that are for sale. Is this just something for handling purposes?

Those are tube dampers. They allegedly cut down/eliminate tube vibration.

Ah, now I remember. Thanks.

"What I might do instead of REPLACE every year is to ROLL every year."

Um, isn't that the same as replacing them?

Since I’ve settled on my current setup, about fifteen years ago, I’ve only had to replace two tubes and that was because a shelf collapsed and dropped my turntable motor controller on the power supply of my phonostage (it uses two 300b tubes as rectifiers).  Other than that, not one tube in 26 that are in my sysrem has gone bad.

Yes, change those bad year-old tubes. Send them to me, I'll take care of them.

@silverfoxvtx1800 ICYI: https://www.head-fi.org/threads/the-reference-6sn7-thread.117677/

As a blanket statement, that's stupid advice.  Tube rectifiers last 10,000+ hours.  Miniature tubes usually last 5,000 to 10,000 hours in most equipment (not necessarily AR gear).  My subminiature tubes are rated for up to 100,000 hours. Only output tubes last typically from 2,000 to 5,000 hours (AR gear I've known-3,000 hours or less, EAR gear 5,000 hours).  Dynaco Mark III amps burned out output tubes every 9 months to a year for me back in the 1980s as they were poorly designed and pushed the tubes very hard.